<html>

<head>
    <meta charset="utf-8" />
    <title>这是标题</title>
    <style>
        span {
            /* 下划线 */
            text-decoration: underline;
        }

        #oneClass {
            /* 中划线 */
            text-decoration: line-through;
        }
    </style>
</head>



<body>
    <p id="one">所在城市:<span>北京</span></p>
    <p id="two">原价<span id="oneClass">19</span>,现价9.9!</p>
</body>

</html>